What are connotations of horizontal and vertical lines in composition?

Question

From my question on diagonal dominance I learned that diagonals are used in many subtle ways, like guiding viewer's eye, expressing depth or energy.

How do horizontal and vertical lines affect viewer's perception of composition - do they have some unique connotations or are they just opposite of diagonals?

Answer

Vertical lines tend to imply strength and power (think supporting columns of a structure, tree trunks, things standing or growing, reaching up or out)

Horizontal lines tend to imply calm, balance or stability (think horizons, oceans, landscapes in general, things at rest)

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